/**
*      author: Y_Yao
*      created: 2025-01-24 22:19:42
**/

#include<bits/stdc++.h>

#define int LL
using namespace std;
using LL = long long;
const LL LLINF = 1e18;
const int INF = 0x3f3f3f3f;
char ab,ac,bc;

void solve()
{
    cin >> ab >> ac >> bc;
    if(ab == '<')
    {
        if(bc == '<')
        {
            cout << 'B' << endl;
        }
        else
        {
            if(ac == '<') cout << 'C' << endl;
            else cout << 'A' << endl;
        }
    }
    else
    {
        if(ac == '<')
        {
            cout << 'A' << endl;
        }
        else
        {
            if(bc == '<') cout << 'C' << endl;
            else cout << 'B' << endl;
        }
    }
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    //cin >> t;
    while(t--)
    {
        solve();
    }
    return 0;
}